An Allele which express itself during gamete formation is termed as:

Alleles occur in pairs. Out of two alleles, only one allele expresses itself in the hybrid and prevents the expression of the other allele. The allele which expresses itself in the hybrid is called dominant allele and the other allele which is unable to express in the hybrid is termed as recessive allele.

a. the production of carbon dioxide through the process of photosynthesis

thats not even an aswer choice